An Evaluation of Serum Based Indices to Assess Fracture Healing

摘要 骨折是人类最常见的大器官、创伤性损伤，也是骨关节炎相关骨折 是老龄化中增长最快的健康问题。虽然手术后的骨折修复通常是最佳的， 在美国每年发生的约800万至1000万例骨折中， 延迟或受损的愈合（Praemer等人，1992年）。目前，放射学评估，减少 愈合并发症和经验证的患者报告的恢复无疼痛负重的结局， 功能是评估骨折愈合进展的主要诊断工具。然而，这些都不是 目前的评估要么定义了与疾病进展相关的潜在生物学过程， 骨折愈合或它们是延迟愈合或不愈合的预后。因此，有一个巨大的， 迫切需要确定客观的可量化的生物标志物：1）与潜在的生物学特征相关的 骨骼组织愈合的过程：2）指示骨骼组织愈合的进展：3） 将是骨骼组织愈合缺陷的预后。这种检测方法的发展将是一个 巨大的益处：1）提供延迟愈合和愈合失败的根本原因的信息; 2）用于临床 评估促进骨愈合的生物学或药理学疗法的疗效的试验，以及：3） 确定将从生物或药理学治疗干预中获益的患者， 促进骨骼愈合。我们的假设是，将有一个血清标志物的组合，可用于 定义骨折愈合的生物学进展，我们将能够将其中一个或多个 标志物的结构，功能和临床特征，定义愈合的进展。两个具体 提出了目标。目的1将确定血清蛋白质组中那些显示出变化水平的蛋白质， 相对于未骨折的骨，在骨折愈合的时间过程中的表达。为此，有两种方法 将使用：质谱方法和更具针对性的新型基于适体的多重蛋白质组学 技术.这一目标是将识别和提供一个子集的蛋白质的初步定量， 与定义骨折愈合时间进程的各种生物过程相关。在目标2中， 将测试这些蛋白质的子集与软骨发育和吸收的统计相关性， 骨和骨痂组织结构矿化的发育和重塑， 对比增强和标准µCT。我们将测试特定蛋白质表达的统计相关性， 特定的生物力学功能（刚度、强度、失效功）。最后，我们将测试愈伤组织的结构， 功能测量和特异性蛋白标记物与当前临床使用的放射学联合 胫骨（RUST）骨折愈合评分（Whelan等人，2010年），用于评估人类的进展 长骨愈合如果成功的话，这项研究将确定一组蛋白质，可以用于人体试验， 其对骨折愈合的诊断功效以及对延迟愈合或失败愈合的预后功效。

ABSTRACT Fractures are the most common large-organ, traumatic injuries in humans, and osteoporosis-related fractures are the fastest growing health care problem of aging. While fracture repair after surgery is usually optimal, up to 10% percent of the estimated ~8 to 10 million fractures that occur annually in the United States show delayed or impaired healing (Praemer et al., 1992). Currently, radiographic assessment, with reduction in healing complication and validated patient reported outcomes of regain of pain free weight bearing and function are the primary diagnostic tools to assess the progression of fracture healing. However none of these current assessments either define underlying biological processes that are related to the progression of fracture healing or are they prognostic for delayed healing or non-unions. Thus, there is an immense and immediate need to identify objective quantifiable biological markers: 1) that relate to the underlying biological processes of skeletal tissue healing: 2) that are indicative of the progression of skeletal tissue healing:3) that would be prognostic of deficiencies in skeletal tissue healing. The development of such an assay would be an immense benefit to: 1) be informative to the underlying causes for delayed and failed healing: 2) use in clinical trials that assess the efficacy of biological or pharmacological therapies that promote bone healing and: 3) identify those patients that would benefit from biological or pharmacological therapeutic interventions to promote bone healing. Our hypothesis is that there will be a combination of serum markers that can be used to define the biological progression of fracture healing and that we will be able to relate one or more of these markers to structural, functional and clinical characteristics that define the progression of healing. Two specific aims are proposed. Aim 1 will identify those proteins in the serum proteome that show changed levels of expression across the time course of fracture healing relative to unfractured bone. In this aim, two approaches will be used: a mass spectrometry approach and a more targeted novel aptamer-based multiplexed proteomic technology. This aim is will identify and provide preliminary quantification of a subset of proteins that can be related to various biological processes that define the temporal progression of fracture healing. In Aim 2, we will test a subset of these proteins for their statistical correlation to the development and resorption of cartilage, development and remodeling of bone and callus tissue structure mineralization as determined by both cartilage contrast enhanced and standard µCT. We will test for statistical correlation of specific protein expression to specific biomechanical functions (stiffness, strength, work to failure). Finally, we will test how callus structure, function measurements and specific protein markers correlate to current clinically used Radiographic Union Score for Tibial (RUST) fracture healing (Whelan et al., 2010) that is used to assess the progression of human long bone healing. If successful this study will identify a set of proteins that can be used in a human trial to test for their diagnostic efficacy to follow fracture healing and their prognostic efficacy for delayed or failed healing.